Fluid actuated hammer



March 12, 1940. E. G. EPPENS FLUID ACTUATED HAMMER Filed April 28, 1938 2 Shuts-Sheet 1 HIS ATTORNEY.

llllll I IIIIIII'I ll'llIl-Illllllll Man-ch12, 1940. PPENS 2,193,166

FLUID ACTUATED HAMMER Filed April 28, 1938' 2 Sheets-Shae; 2

5,9 INVENTOR HIS ATTORNEY.

Patented Mar. 12, 1940 PATENT OFFlCE FLUID ACTUATED HAlWll/IER Ernest G. Eppens, Easton, Pa., assignor to Ingersoll-Rand Company, Jersey City, N. J., a

corporation of New Jersey Application April 28, 1938, Serial No. 204,729

Claims.

This invention relates to fluid actuated hammers, and more particularly to fluid actuated hammers of the type employed for drop forging and similar purposes.

One object of the invention is to render the hammer readily responsive to the will of the operator.

Another object is to limit the power consumption of the hammer to substantially that required for performing useful work.

Another object is to simplify and reduce the cost of manufacture of the control mechanism of the hammer.

A further object is to enable the hammer to be selectively held stationary at the ends of its strokes.

Other objects will be in part obvious and in part pointed out hereinafter.

In the drawings accompanying this specification and in which similar reference numerals refer to similar parts,

Figure 1 is a perspective view in elevation, partly broken away, of a fluid actuated hammer constructed in accordance with the practice of the invention,

Figure 2 is a transverse view taken through Figure 1 on the line 2--2,

Figure 3 is a side elevation, partly broken away, of a detail, and

Figure 4 is an elevation, partly broken away, of a portion of the hammer and the valve mechanism whereby the hammer is controlled.

Referring more particularly to the drawings, the hammer, designated in its entirety by 20, comprises the usual main frame consisting of a pair of columns 2| between which is interposed an anvil block 22 to support a stationary die member 23.

The columns 2| support a vertical cylinder 24 having a piston chamber 25 to accommodate a reciprocatory piston 26. Suitable closures 21 and 28 are provided for the upperand lower ends, respectively, of the cylinder, and the closure 28 serves the additional function of a guide for a piston rod 29 carrying a ram 30 which in turn carries a complementary die member 3|.

The parts so far described, their arrangement and mode of operation are well known and inasmuch as they form no part of the present invention, which is concerned more particularly with the valve mechanism designated 32, further detailed description thereof is deemed unnecessary.

The valve mechanism 32 is preferably arranged immediately adjacent thepiston chamber 25 and the cylinder 24 is accordingly provided with an enlargement which is bored to receive a bushing 33 of which the interior serves as a valve chamber 34 for a throttle valve 35. The throttle valve 35 is of the sleeve reciprocatory type and is provided with series of ports 36, 31 and 38 adapted to register with other groups of ports 39, 40 and 4|, respectively, in the bushing 33.

In the enlargement or valve chest 42 containing the valve mechanism are annular grooves 43, 44 and 45 that encircle the ports 39,40 and 41, respectively. The ports 39, 40 and 4] are arranged in the order named from the upper portion of the valve mechanism, and leading from the groove 43 to the uppermost end of the pis- 15 ton chamber 25 is a passage 46 which serves both to convey pressure fluid to the upper end of the piston chamber and the exhaust fluid therefrom.

In like manner, communication is afforded between the groove 45 and the lowermost end of the piston chamber by a passage 41 which also serves the dual function of inlet and exhaust passage.

The ports 49 are located between the ports 39 and 4|. They are in constant communication with the groove 44 which forms the outlet open ing for asupply chamber 48 having a port 49 for the entranceof pressure. fluid from a source of supply (not shown).

In what may be called the off position of the throttle valve the several series of ports in its wall lie above the ports in the bushing 33 wherewith they are intended to register, the throttle valve being held in this position by a spring 50, in the bushing 33, acting against the lower end of the throttle valve 35. Thus, in the absence of pressure tending to move the throttle valve into position for bringing its ports into registry with those in the bushing 33 the spring 50 will maintain the throttle valve in its uppermost limiting position in which the blank spaces below the ports 36, 3! and 38 will overlie and seal the ports 39, and M.

Any suitable and well known devices may be provided for actuating the throttle valve to its 45 open position. i The means illustrated comprises -a connecting rod 51 which is arranged eccentrically of the valve 35 and pivotally on a, wri t pin 52 disposed in the lowermost portion of the throttle valve. The opposite end of the conmeeting rod 5| is pivotally connected to an arm 53 arranged angularly with respect to the connecting rod and keyed to a sleeve 54 rotatable in a boss 55 carried by the cylinder 24.

The sleeve 54 extends exteriorly of the boss 55 55 and carries on its opposite end an arm 56 which is locked to the sleeve by a key 51. The arm 96 preferably lies in the same plane as the arm 93 and carries on its free end va pin 58 which serves as an anchor for an end of a cable 59 of which the opposite end is connected to the free end of a rocker arm 69 located near the base of the hammer. Preferably the intermediate portion of the cable 59 is trained over arocker sheave 9! carried by a bearing 92 on a column 25 in order to maintain the cable out of the range of movement of the operator.

The rocker arm 99 is arranged approximately normal to the adjacent column 2| and may be suitably interlocked with a bar 69 journalled in bearings 99, only one being shown, and carrying a treadle 99 upon which the operator may step for imparting opening movement to the throttle valve 39.

In the form of the invention shown the throttle valve 99 also serves as a valve chest and ac cordingly contains a distributing valve 99 of the reciprocatory type, which serves to valve pressure fluid from the ports 31 to the passages 45 and t? and also to control the exhaust of fluid from the ends of the piston chamber 29. The valve is hollow, having a hole 9? extending entirely therethrough, and is provided on its periphery with an annular groove 99 constituting a supply chamber 69 which is in constant communication with the ports 97 for supplying pressure fluid to the passages iti and All.

At the lower and upper ends of the groove 68 are flanges i9 and H, respectively, which are so spaced with respect to each other that when the valves 99 and 99 are in the positions which they will assume during the time the hammer is idle that they will overlie the ports 99 and 99, respectively. The portion. of the valve 99 lying immediately above the flange ii is of smaller diameter than the interior of the valve 39 and has radial ports it through which fluid exhausted from the upperend of the cylinder 25 may flow into the valves 66 and 95, whence it passes through an exhaust chamber 39 in the hammer casing and an exhaust port it to the atmosphere.

On the upper end of the valve 99 is a seat 15 for a spring l9 seating against a cap il overlying the valve chest, and acting to constantly urge the valve 99 downwardly.

The linkage through which power is transmitted for raising the valve 99 comprises a rod ?8 which is pivctally connected to the upper end of said valve by a pin 19 and is similarly con.- nected at its lower end with an arm 89 arranged angularly to the rod 19 and carried by a shaft 9! journalled in the sleeve M'wherein it is freely rotatable. The shaft 9i projects with its opposite end from the end of the sleeve 94 and carries a second arm 92 which is arranged in substantially the same angular relationship with respect to the rod l8 as the arm 89 and has its free end pivotally connected to a link '83.

The link 33 depends from the arm 92 and forms a connection between said arm and a rocker arm 94 mounted pivotally upon a rod or shaft 95 arranged in a bearing 99 secured to a column 2| by bolts 9?. The link 89 is adjustable. It comprises a pair of rods 89 and 99 of which the rod 88 is directly connected to the arm 82 and the rod 99 is connected to the free end of the rocker arm 89. The rods 99 and 99 are threadedly connected to each other so that by rotating one of the rods, in the arrangement shown the rod 89, the link 83 may be shortened or lengthened to determine the degree of movement of the rocker arm.

The rod 89 is journalled in a bearing 99 pivotally arranged in the arm 84 and has a shoulder 9! that seats upon the bearing 99, and beneath the bearing 99 and encircling the rod 89 is a spacer 92 of which the exterior is of hexagonal shape to interlockingly engage a correspondingly shaped sleeve 93 slidable thereon. The spacer 92 seats against the bearing 99 and may be held against rotation by extending an end of said spacer into the end of the arm 84.

The rod 99 is freely rotatable in the spacer 92 and such movement may be imparted to the rod for adjusting the link 89 through a bar 94 which extends through the lower end of the rod 89 and through a collar 95 encircling the rod. The collar 95 is of the same conformation externally as the spacer 92 and when the flats of the surfaces of the spacer and the collar 95 are in coincidence the sleeve 93 may be placed in position to interlockingly engage bothfor holding the rod 99 against rotation.

The shaft and, therefore, the rocker arm 84 which it supports is so arranged that the shaft lies closely adjacent the path of movement of the ram 99, and on the arm 89 and arranged angularly with respect thereto is a depending finger 96 having a convex surface 9'! for engagement with an inclined surface 98 on the side of the ram 39. The arrangement is such that as the ram 39 is raised the surface 98 moves into engagement with the convex surface 91 and rocks the finger outwardly. This movement of the finger is transmitted by the connecting linkage to the valve 96 for actuating said valve in the direction required to communicate the passage 46 with the supply chamber 69. V

During the descending movement of the ram the inclined surface 98 is of course also lowered thus permitting the finger 96 to move inwardly. The spring 19 will then depress the valve 69 and shift the linkage connected thereto to maintain the convex surface 91 of the finger 96 in contact with the inclined surface 98.

In addition to its function of communicating the hammer with the source of pressure fluid supply the thrcttle valve 35 also serves to determine the idle raised position of the ram. The throttle valve is accordingly provided in its periphery with a pair of grooves 99 and I99 of which the groove 99 establishes communication between a port 39 and the interior of the cap 17 in the uppermost limiting position of the throttle valve.

Thus, when the valve occupies this position, the

upper end of the piston chamber will be in communication with the atmosphere through the groove 93, the port 39, the groove 99 and the openings and spaces affording communication between the interior of the cap 71 and the atmosphere.

The groove 599 serves the function of a bleeder passage and in the raised position of the throttle valve 35 affords communication between a port or ports 49 and a port ll so that when the supply chamber 99 is out of communication with the source of pressure fluid supply pressure fluid will flow through the passage 4'! into the lower end of the piston chamber to move the piston to its uppermost limiting position and hold it stationary. In the depressed or open position of the throttle valve both grooves 9| and I99 will be out of communication with the ports in the bushing 33 and will, therefore, play no part during the normal operation of the hammer.

In order to prevent impact of the piston 26 against the closure 21 when the piston is elevated to the non-idling position after a period of operaclosure 21 into the piston chamber 25 and car- I ries a pad IIlB of cushioning material, as for example wood or rubber, against which the piston 28 may seat.

The uppermost end of the piston chamber IIlZ constitutes apressure chamber which is in constant communication with the supply chamber 48 through a passage I06. Thus, pressure fluid is admitted into the piston chamber I02 above the piston I03 to absorb the impact of the piston 26 when it strikes the pad I05 and the piston 26 will be brought to rest before it may strike against the closure 21. Y

Preferably, a bevelled surface III'I is formed on the piston adjacent the extension IM and a cor responding seating surface I08 is provided on the upper part of the closure 2 to cooperate with the surface IIII for eifecting a seal between the piston chambers 25 and I02. The surfaces I81 and I08 are of considerable width and an annular groove I09 is formed in the surface I08 to intercept any fluid which may flow from either piston chamber. A vent III], in the closure 2'1, communicates the groove I09 with the atmosphere.

Whenever it is intended to operate the hammer the operator partly depresses the treadle 65. Movement is thereby transmitted to the valve 35 through the connecting linkage for pulling the valve downwardly to bring its ports into registry with the ports in the bushing 33.

With the valve 35 in the new position the up per end of the piston chamber 25 will be in communication with the supply chamber 69 through the passage 46 and the ports 33 and 36, and the lower end of the piston chamber 25 will be in communication with the exhaust port I4 through the passage 41, the ports 4| and 38, the interiors of the valve 35 and the bushing 33 and the chamber I3. Pressure fluid entering the upper end of the piston chamber 25 I will then drive the piston 26 downwardly to deliver a stroke upon the work interposed between the die members 23 and 3|.

During the descending movement of the piston the inclined surface 98 will, of course, move downwardly, thus permitting the finger 96 to be rocked inwardly by the force of the spring I6. The distributing valve will then move downwardly to a position in which the flange I0 uncovers the ports 38 and the flange II will cut off communication between the supply chamber 69 and the ports 36 and place the latter ports in communication with the space above the flange I I. The fluid utilized for driving the piston 26 downwardly will then exhaust into the cap I1 and pass through the ports I2, the valves 66 and 35, the chamber I3 and the exhaust port M to the atmosphere.

At the same time the lower end of the piston chamber 25 will be charged. The piston 26 will then move toward the upper end of the piston chamber 25 and the inclined surface 98 will rockthe finger 96 outwardly. This movement of the finger, transmitted through the linkage connecting the finger with the valve 66, will cause the valve 66 to again be elevated to its uppermost limiting position for charging the upper end of the, piston chamber 25 and to uncover the ports II for opening the lower end of the piston chamber, 25 to the atmosphere.

The described cycle of operation may be repeated as often as may be necessary to complete the work and in the event that it be desired to maintain the ram 38 upon the work for clamping it between the die members the treadle 85 may be further depressed. By so doing the throttle valve is moved downwardly to a position in which the ports 38, while still in communication with the ports 4|, will occupy a position in which the lower portion of said ports liebelow the flange ID in the lowermost limitson that the uppermost portions of the ports.

will lie at a lower elevation than may be reached by the upper edge of the flange I0, hence no pressure fluid may be admitted into the lower end of the piston chamber.

By depressing the throttle valve in the manner described the ports 36 will, of course, also be moved downwardly, and although still in registry with the ports 39, they will lie at too low an elevation to be covered by the flange II. Pressure fluid will, therefore, have free entry into the upper portion of the piston chamber 25 and .move the ram 36 downwardly and hold it against the work.

After the need for clamping the work between the dies has passed the pressure on the treadle 65 may be relieved somewhat. The spring 50 will then raise the valve 35 to a position where the ports 38 will again establish communication between the supply chamber 69 and the lower part of the piston chamber 25 to elevate the piston 26 preparatory to the beginning of a new'forging operation, or to retain the piston 26 stationary in the uppermost portion of the piston chamber in the manner previously described.

I claim:

1. In a fluid actuatedhammer, the "combination of a casing having a piston chamber and a reciprocatory piston therein, passages for conveying pressure fluid to the ends of the piston chamber, a throttle valve having a pressure fluid supply chamber, and a valve in the throttle valve to effect the distribution of pressure fluid from the supply chamber to the passages.

2. In a fluid actuated hammer, the combination of a casing having a piston chamber and a reciprocatory piston therein, passages for conveying pressure fluid to and exhaust fluid from the piston chamber, a throttle valve having a supply chamber and ports to communicate the supply chamber with the passages, and a reciprocatory valve in the supply chamber to control the flow of pressure fluid into and the exhaust of fluid from the ports.

3. In a fluid actuated hammer, the combination of a casing having a piston chamber and a reciprocatory piston therein, passages for conveying pressure fluid to and exhaust fluid from the piston chamber, a reciprocatory throttle valve having a supply chamber for pressure fluid and ports to register with the passages in an intermediate position of the throttle valve, and a distributing valve to control the admission of pressure fluid to and the exhaust of fluid from the piston chamber for actuating the piston and to admit pressure fluid into an end of the piston chamber in a limiting position of the throttle valve for holding the piston stationary.

4. In a fluid actuated hammer, the combination of a casing having a piston chamber and a reciprocatory piston therein, passages for conveying pressure fluid to and exhaust fluid from the piston chamber, a reciprocatory throttle valve having a supply chamber for pressure fluid and ports to register with the passages in an intermediate position of the throttle valve, and a distributing valve reciprocable in the throttle valve to control the ports for efiecting actuation of the piston and to communicate the upper end of the piston chamber with supply and the lower end of said piston chamber with the atmosphere in a limiting position of the throttle valve to hold the piston stationary in the lower end of the piston chamber.

.sure fluid to and exhausting fluid from the piston chamber for actuating the piston, a vent in the throttle valve to connect the upper passage with the atmosphere in a limiting position of the throttle valve, and a bleeder passage in the throttle to register with the lower passage in said limiting position of the throttle valve to admit pressure fluid into the lower end of the piston chamber to hold the piston immovable.

ERNEST G. EPPENS. 

